Anas ibn Malik reported: The Prophet, peace and blessings be upon him, drew some lines in the sand and he said, “This one is the worldly hopes of man and the other is his lifespan. A man will continue like this until the other line overtakes him.”
Source: Ṣaḥīḥ al-Bukhārī 6418
Grade: Sahih (authentic) according to Al-Bukhari
عَنْ أَنَسٍ قَالَ خَطَّ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ خُطُوطًا فَقَالَ هَذَا الْأَمَلُ وَهَذَا أَجَلُهُ فَبَيْنَمَا هُوَ كَذَلِكَ إِذْ جَاءَهُ الْخَطُّ الْأَقْرَبُ
6418 صحيح البخاري كتاب الرقاق باب في الأمل وطوله