بُلُوغُ الْمَرَامِ
Bulugh al-Maram 508
The Book of Prayer
وَلَهُ: عَنْ جَابِرٍ - رضى الله عنه - { صَلَّى سِتَّ رَكَعَاتٍ بِأَرْبَعِ سَجَدَاتٍ } [1] .
He also reported from Jabir (RA): "He [Allah's Messenger (ﷺ)] performed six bowings with four prostrations (in a two Rak'ah prayer for Eclipse)."
Sunnah.com reference: Book 2, Hadith 438