It wasnarrated that 'Abdullah bin 'Amr said:
"The Messenger of Allah(ﷺ) said: 'Do not be like so-and-so, who used to pray voluntarynight prayers then stopped praying voluntary night prayers." (PT)
English reference (PT): Vol. 1, Book 5, Hadith 1331 (PT)
Arabic reference (PT): Book 5, Hadith 1392 (PT)