سُبْحانَ الَّذِي يُسَبِّحُ الرَّعْدُ بِحَمْدِهِ، وَالمَلائِكَةُ مِنْ خِيْفَتِهِ
When Abdullah Ibn Az-Zubayr (ra) used to hear thunder he would stop talking and say:
‘How perfect He is, (The One) Whom the thunder declares His perfection with His praise, as do the angles out of fear of Him.’
Source: Hisnul Muslim