It is reported that Bakr b. ʿAbdillāh Al-Muzanī – Allāh have mercy on him – said:

If you want your ṣalāh to benefit you, say (to yourself): perhaps I will never pray another (my life will end before the next prayer).

Ibn Abī Al-Dunyā, Qaṣr Al-ʾAmal article 104.