Riyad as-Salihin 18
'Abdullah bin 'Umar bin Al-Khattab (May Allah be pleased with them) reported that:
The Prophet (ﷺ) said, "Allah accepts a slave's repentance as long as the latter is not on his death bed (that is, before the soul of the dying person reaches the throat)". [At-Tirmidhi, who categorised it as Hadith Hasan] .
وعن أبي عبد الرحمن عبد الله بن عمر بن الخطاب رضي الله عنهما عن النبي صلى الله عليه وسلم قال‏:‏ ‏
"‏ إن الله عز وجل يقبل توبة العبد ما لم يغرغر‏"‏ ‏(‏‏(‏رواه الترمذي وقال‏:‏ حديث حسن‏)‏‏)‏‏.‏