Abu ar-Reyhaan al-Bayrooni was a prolific thinker and writer whose pen rarely left his hand. He lived to the ripe age of seventy- eight and throughout his life he never unnecessarily took a break from reading, writing, or teaching.
Abul Hasan 'Ali ibn 'Eesa said:
"I visited Abu ar-Reyhaan when he was on his deathbed. Upon entering, l immediately recognized that he was on the verge of leaving this life. While in that state, he said to me that there was an issue in (Islamic) inheritance law that we had discussed the last time we met and that I had said something then that he now realized was a mistake. I felt compassion for him, and asked him if it was proper for him to discuss something like that, with him being so ill. He answered, 'I know that I am leaving this world, but don't you think it is better for me to understand the issue in question than to be ignorant of it?' I then repeated to him the issue, and he started to explain it to me. After we finished our conversation, I left, and upon exiting, I heard a scream and I knew that he had died. It is only lofty souls like his that remain strong right until the end."
When 'Umar was bleeding to death after being stabbed, he asked his companions whether he had completed the prayer or not.
Ibraheem ibn al-Jarrah said:
"Abu Yusuf became sick and was vacillating between wakefulness and unconsciousness. When he regained consciousness, he asked me about a religious issue. When he saw the wonder with which I received his question, he said to me, 'No matter, we will study this issue in the hope that the knowledge of it perpetuates until it becomes the cause of saving someone."'
This is how our pious predecessors were. Every time they revived, while yet being on their deathbeds, they would talk about Islamic knowledge, either as a teacher or as a student. How precious was knowledge to their hearts! In the last moments of their lives, they remembered neither family nor wealth; they only remembered the knowledge that was the toil of their lives. May Allah have mercy upon them.