ENOfficial
Abu Dharr said that God’s messenger was asked what words were most excellent and replied, “What God has chosen for His angles: Glory be to God and I begin with praise of Him.” Muslim transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ أَبِي ذَرٍّ قَالَ: سُئِلَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَيُّ الْكَلَامِ أَفْضَلُ؟ قَالَ: " مَا اصْطَفَى اللَّهُ لِمَلَائِكَتِهِ: سُبْحَانَ اللَّهِ وَبِحَمْدِهِ ". رَوَاهُ مُسلم
sunnah.com