the phrase in sha Allah means as follows
in = if
sha= wishes
Allah=God
Basically it means "If Allah wishes" or "God willing" it is said after talking about some future event in recognition that everything happens only if Allah wills it and He has total power over our lives e.g "Im going to visit my family next week inshAllah"
Insha'Allah (إن شاء الله) is an Arabic term evoked by Muslims to indicate hope for an aforementioned event to occur in the future. The phrase translates into English as "If it is God's will".
The term is also related to another Arabic term, Masha'Allah (ما شاء الله), which means "God has willed it".
This word is often used to indicate a desire to do something that may not actually occur. In Judaism, B'ezrat Hashem (בעזרת השם) and Im Irtze Hashem (אם ירצה השם) are used for the same reason.
Usage of Insha'Allah derives from Islamic scripture, Surat Al Kahf (18):24 : "And never say of anything, 'I shall do such and such thing tomorrow. Except (with the saying): 'If Allah wills!' And remember your lord when you forget..."
[edit] Historical reference
Muslim scholar Ibn Abbas stated that it is in fact obligatory for a Muslim to say Insha'Allah when referring to something he or she intends to do in the future. If carelessness leads to the omission of the phrase, it may be said at a later time upon the realization of the omission.
The Spanish word ojalá and the Portuguese word oxalá (I hope, I wish) are derived from law šá lláh, a similar phrase meaning "God willing." They are an example of the many words borrowed from Arabic due to the Muslim occupation of Iberian peninsula from the eighth to fifteenth centuries.
http://en.wikipedia.org/wiki/Insha'Allah
With regards weeping over the dead - it is a sign of mercy in the heart - what is prohibited in Islam is wailing beating yourseves or being angry with God (God forbid)
WEEPING FOR THE DEAD
1. The Messenger of Allah (S.A.W.) wept on the death of his son Ibrahim.
The following narration has been mentioned in Sahih Bukhari, Sahih Muslim, Sunan Abi Dawood and Sunan Ibne Majah:
Anas bin Malik reported that: The Messenger of Allah (S.A.W.) entered the room and we accompanied him... And Ibrahim breathed his last. The eyes of Allah's Messenger (S.A.W.) were filled with tears. Abdur Rehman Ibne Auf said: 'you are weeping, O Messenger of Allah (S.A.W.)'. He (S.A.W.) replied: "Ibne Auf, This is mercy". Then he (S.A.W.) said: "Our eyes shed tears and our hearts are filled with grief, but we do not say anything except that by which Allah is pleased. O, Ibrahim we are sorrowful due to your separation."
And it is mentioned in Sunan Ibne Majah that: Anas Ibne Malik says: When Ibrahim the son of the Prophet (S.A.W.) died, he (S.A.W.) said: "Do not shroud him till I have looked at him." Then he came forward in misery and wept.
In Sunan Tirmizi it is recorded from Jabir Ibne Abdulla Ansari that:
The Messenger of Allah (S.A.W.) held the hand of Abdur Rehman Ibne Auf and took him to Ibrahim, his son, when Ibrahim was in his last moments. The Messenger of Allah (S.A.W.) took him in his lap and began to weep. Abdur Rehman Ibne Auf said: 'you are weeping? And you had yourself prohibited weeping?' The Messenger of Allah (S.A.W.) replied: 'No, but I had prohibited two kinds of cries of foolish and sinful people: The cry at the time of a calamity, and tearing at the face and the collar. And the second is crying like Shaitan. And there is more in this narration. Abu Isa says that this hadith is good.
2. The Messenger of Allah (S.A.W.) wept for his Uncle Hamza (R.A.).
The books Tabaqat Ibne Saad, Maghazi of Waqidi and Musnad Ahmed Hanbal mention the following tradition:
After the Battle of Uhud, the Messenger of Allah (S.A.W.) passed by a house of Ansars. He heard the wailing of the people for their martyred family members. The eyes of the Messenger of Allah (S.A.W.) filled with tears and he began to weep. Then he (S.A.W.) said: "But there is no one to weep for Hamza." When the ladies of the family of Sa'ad bin Muadh and Usayd bin Huzayr al-Ashhal returned they told them to go and weep for Hamza, the uncle of the Prophet (S.A.W.). Then from that time to date none of the women of Ansar have wept for their dead ones before weeping upon Hamza (R.A.).
3. The Messenger of Allah (S.A.W.) wept for Jafar bin Abi Talib (R.A.).
Certainly you have in the Messenger of Allah an excellent exemplar for him who hopes in Allah and the latter day and remembers Allah much.
- Holy Qur'an (33:21)
A narration recorded in the books of Al-Istiab, Usud al-Ghaba, Al-Isabah and Ibne Athir etc that: When Jafar was killed with his companions, the Messenger of Allah (S.A.W.) came to his house and summoned his children. Then he consoled them up and there were tears in his eyes. Asma, the wife of Jafar said: May my parents sacrificed for you, you are crying? Shall I tell you about Jafar and his companions?
"Yes", he replied the Messenger of Allah (S.A.W.), "I am very sorrowful today."
Then Asma called and the women gathered, and Fatima (S.A.) entered weeping and wailing, "O Uncle!".
The Messenger of Allah (S.A.W.) said: "A brave one like Jafar deserves to be wept upon."
4. The Messenger of Allah (S.A.W.) wept for his mother at her grave.
Many books of traditions like Sahih Muslim, Musnad Ahmed Hanbal, Sunan Abi Dawood, Sunan Nasai and Sunan Ibne Majah mentioned the following tradition:
Abu Huraira says: "The Prophet (S.A.W.) visited the grave of his mother and wept and made others weep too."
5. The Messenger of Allah (S.A.W.) wept for his grandson, Hussain (A.S.) on various occasions.
(i) Tradition of Ummul Fazl.
The first narration quoted by us is recorded in Mustadrakul Sahihayn, History of Ibne Asakir and Maqtal of Khwarizmi, other books also mention this incident.
Ummul Fazl the daughter of Harith came to the Messenger of Allah (S.A.W.) and said: "O Messenger of Allah (S.A.W.), I had a dream in which I saw that a piece of your flesh flew off and fell into my lap. The Messenger of Allah (S.A.W.) told her, "You have seen something good, by the will of Allah, Fatima will give birth to a child and you will be present in the house."
Later Fatima (S.A.) gave birth to Hussain (A.S.) and Ummul Fazl was present, as the Prophet (S.A.W.) had predicted. She placed Hussain (A.S.) in the lap of the Prophet (S.A.W.), She said:
"Thus when I saw the Messenger of Allah (S.A.W.) that his eyes were filled with tears. I said, 'O Messenger of Allah (S.A.W.), may my parents be sacrificed for you, why are you weeping?'.
He (S.A.W.) replied, 'Jibraeel came to me and informed me that my people will soon murder this son of mine.'
I asked, 'This son?'
'Yes', he (S.A.W.) replied, 'And he gave me the red dust of his grave.'
Al-Hakim says, "This is an authentic hadith according to the standards of Bukhari and Muslim, but they have not included it in their collections."
(ii) Tradition of Zainab Binte Jahash
A similar type of narration has been presented in the books: Tarikh Ibne Asakir, Majmauz Zawaed, Tarikh Ibne Kathir etc:
Zainab says: One day while Hussain (A.S.) was in my house and near me at the staircase, and then I became thoughtless. The Messenger of Allah (S.A.W.) entered.... He (S.A.W.) said, "Let him be (as he is). The Prophet (S.A.W.) stretched out his hands while he was performing the prayers and took Hussain (A.S.) to him. I said, "O Messenger of Allah (S.A.W.), I have never seen you do this before?"
He (S.A.W.) said, "Jibraeel came to me and informed me that this (Hussain) will be killed by my Ummat." I requested him, "Then show me the dust of the land, where he will be killed." And he gave me some red earth.
(iii) Tradition of Ayesha (R.A.)
Abi Salma has been recorded in Tarikh Ibne Asakir, Maqtal Khwarizmi and Majmauz Zawaid to say:
Ayesha (R.A.) said: The Messenger of Allah (S.A.W.) had seated Hussain (A.S.) upon his thigh when Jibraeel came and asked, "Is this your son?"
"Yes", he replied.
Jibraeel said, "But your Ummat will soon kill him after your demise."
The eyes of the Prophet filled with tears.
Jibraeel said, "Would you like to see the land where he shall be killed?"
"Yes", he replied.
Then Jibraeel showed him the fine dust of his grave.
In another narration there is a variation where Jibraeel is reported to have indicated towards Iraq and took some red dust from it and showed it to him and said, "This is the dust from his fatal battleground."
(iv) Tradition of Umm-e-Salma (R.A.)
Mustadrakul Sahihayn, Tabaqaat Ibne Saad, Tarikh Ibne Asakir and other books have mentioned the following tradition from Umm-e-Salma (R.A.):
The Messenger of Allah (S.A.W.) was sleeping one night when he awoke with a start. He was in a state of terror. Then again he went to sleep and once more woke up with a start. This time he was more worried. Again he went to sleep and woke up. In his hands was some red dust. He was turning it around in his hands.
She said, "What is this dust, O Messenger of Allah?" He said, "Jibraeel informed me that this Hussain will be killed in the land of Iraq. I asked Jibraeel to show me the dust of the land where he will be killed. And this is that dust."
The Messenger of Allah (S.A.W.) told Umar not to prohibit weeping.
The books of Sunan Nasai, Sunan Ibne Majah and Musnad Ibne Hanbal record the following narration:
Salma binte Azraq reports that Abu Huraira said: Someone of the family of the Messenger of Allah (S.A.W.) died. The women gathered and began to weep upon the death. Umar stood up and refrained them from weeping. The Messenger of Allah (S.A.W.) said: Do not stop them, Umar, because the eyes weep and the heart is sorrowful and it has been only a short while (since the calamity).
And in Musnad Ahmed Hanbal:
From Wahab bin kaysani, from Muhammad bin Umar that he informed him: Salma Ibne Azrak was sitting with Abdullah Ibne Umar in the market place when a bier passed and people were weeping on it. When Abdullah Ibne Umar restrained them from weeping, Salma Ibne Azraq told him; do not say that, because I have witnessed my father say that he heard from Abu Huraira that a woman from the family of Marwan died and Marwan told his women not to weep upon her. Abu Huraira told him not to restrain them as he himself had witnessed the incident when the Messenger of Allah (S.A.W.) told Umar not to send away the women who were weeping upon the dead. Moreover, the Messenger of Allah (S.A.W.) had said: "Call them back, son of Khattab, for surely the soul is sorrowful and the eyes weep and it is a fresh incident."
He said, "Did you not hear him say that?".
"Yes", he replied, "The Almighty and His Messenger are more knowledgeable."