Abu Dharr (RA) reported that Allah's Messenger (ﷺ) was asked as to which words were the best. He said: Those for which Allah made a choice for His Angels and His servants (and the words are): "Hallowed be Allah and praise is due to Him."
Hadith Referenceصحيح مسلم / كتاب الذكر والدعاء والتوبة والاستغفار / 2731
Abu Dharr (RA) reported that Allah's Messenger (ﷺ) said: Should I not inform you about the words liked most by Allah? I said: Allah's Messenger, do inform me about the words liked most by Allah. He said: Verily, the words liked most by Allah are: "Hallowed be Allah and praise is due to Him."
Hadith Referenceصحيح مسلم / كتاب الذكر والدعاء والتوبة والاستغفار / 2731
´Abu Dharr narrated that the Messenger of Allah (ﷺ) visited him, or that Abu Dharr visited the Messenger of Allah (ﷺ), and said:` “May my father and my mother be ransomed for you, O Messenger of Allah (ﷺ)! Which speech is most beloved to Allah [the Mighty and Sublime]?” So he said: “That which Allah selected for His angels (to say): ‘Glory to my Lord, and with His praise. Glory to my Lord, and with His praise (Subḥāna rabbī wa biḥamdihi, subḥāna rabbī wa biḥamdihi).’”
Shaykh Dr. Abdur Rahman Freywai
Explanation: 1: My Lord is pure, and all praise is for Him; My Lord is pure, and every kind of praise is befitting only for Him.
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 3593