Sahih Muslim , Book 15, Hadith 315 (In-Book) ⓘ

Ubaidullah b. 'Abdullah b. 'Umar reported on the authority of his father (Allah be pleased with them) that Allah's Messenger combined the sunset and 'Isha', prayers at Muzdalifa and there was no prostration (i. e. any rak'ahs of Sunan or Nawafil prayers) in between them. He observed three rak'ahs of the sunset prayer and two rak'ahs of the 'Isha' prayer, and 'Abdullah (b. 'Umar) observed the prayers in this very manner (at Muzdalifa) until he met his Lord.

وَحَدَّثَنِي حَرْمَلَةُ بْنُ يَحْيَى، أَخْبَرَنَا ابْنُ وَهْبٍ، أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، أَنَّأَخْبَرَهُ أَنَّ أَبَاهُ قَالَ جَمَعَ رَسُولُ اللَّهِ صلى الله عليه وسلم بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ بِجَمْعٍ لَيْسَ بَيْنَهُمَا سَجْدَةٌ وَصَلَّى الْمَغْرِبَ ثَلاَثَ رَكَعَاتٍ وَصَلَّى الْعِشَاءَ رَكْعَتَيْنِ ‏.‏ فَكَانَ عَبْدُ اللَّهِ يُصَلِّي بِجَمْعٍ كَذَلِكَ حَتَّى لَحِقَ بِاللَّهِ تَعَالَى ‏.‏