Shortly before losing his beloved Khadijah (ضي الله عنها), Prophet Muhammad (صَلّى االلهُ عَلَيْهِ وسَلَّم) lost his uncle and childhood guardian Abu Talib. This is also another reason why that year was referred to as "The Year of Sorrow." Abu Talib was the chief of the Banu Hashim clan and had a certain authority amongst the people of Mecca. He had vowed to protect and care for Prophet Muhammad (صَلّى االلهُ عَلَيْهِ وسَلَّم) and he did so until he died.
Prophet Muhammad (صَلّى االلهُ عَلَيْهِ وسَلَّم) loved his uncle dearly and tried very hard to get him to say the Shadah on his death bed. Abu Talib refused, this greatly saddened Prophet Muhammad (صَلّى االلهُ عَلَيْهِ وسَلَّم). Allah brought down a verse in the Quran about this:
إِنَّكَ لَا تَهْدِي مَنْ أَحْبَبْتَ وَلَٰكِنَّ اللَّهَ يَهْدِي مَن يَشَاءُ وَهُوَ أَعْلَمُ بِالْمُهْتَدِينَ
Innaka la tahdee man ahbabta walakinna Allaha yahdee man yashao wahuwa aAAlamu bialmuhtadeena
You surely cannot guide whoever you like ˹O Prophet˺, but it is Allah Who guides whoever He wills, and He knows best who are ˹fit to be˺ guided. (Surat Al Qasas 28, Ayah 56).
The Prophet's Children
During his life time, the Prophet (صَلّى االلهُ عَلَيْهِ وسَلَّم) lost all of this children with the exception of Fatimah (ضي الله عنها) who died shortly after him.
Imagine outliving almost all of your children and burying each one... The first two kids to die were his sons, Qasim and Abdullah; they both died in infancy. Both of these children were mothered by Khadijah (ضي الله عنها).
His third son, Ibrahim also died at a young age (before he turned two years old). He was mothered by Maaria Al Qibtiyya. She was the only other woman to bear children for the Prophet (صَلّى االلهُ عَلَيْهِ وسَلَّم).
This is how the Prophet (صَلّى االلهُ عَلَيْهِ وسَلَّم) reacted when his son, Ibrahim died:
فعن أنس بن مالك رضي الله عنه قال: دخلنا مع رسول الله صلى الله عليه وسلم على أبي سيف القين، وكان ظِئْرًا لإبراهيم ابن النبي صلى الله عليه وسلم، فأخذ رسول الله صلى الله عليه وسلم إبراهيم فقبَّله وشمَّه، ثم دخل عليه بعد ذلك وإبراهيم يجودُ بنفسه، فجعلتْ عينا رسول الله صلى الله عليه وسلم تذرفان! فقال له عبدالرحمن بن عوف: وأنت يا رسول الله؟ فقال صلى الله عليه وسلم: ((إن العين تدمع، والقلب يحزن، ولا نقول إلا ما يرضي ربنا، وإنا بفراقك يا إبراهيم لمحزونون))
Narrated by Anas Ibn Malik (RA): We went with Allah’s Messenger (PBUH) to the blacksmith Abu Saif (RA), and he was the husband of the wet-nurse of Ibrahim (the son of the Prophet). Allah’s Messenger (PBUH) took Ibrahim and kissed him and later we entered Abu Saif’s house and at that time Ibrahim was in his last breath, and the eyes of Allah’s Messenger (PBUH) started shedding tears. Abd ar-Rahman bin Auf (RA) said, “O Allah’s Apostle, even you are weeping!” He said, “O Ibn Auf, this is mercy.” Then he wept more and said, “The eyes are shedding tears and the heart is grieved, and we will not say except what pleases our Lord, O Ibrahim! Indeed, we are grieved by your separation.”