Praise be to Allah.
This hadeeth has been narrated via a number of isnads (chains of narration) from the great Sahabi (Companion) Abu Umamah (may Allah be pleased with him), that the Messenger of Allah (peace and blessings of Allah be upon him) passed by him when he was moving his lips and he said:
“What are you saying, O Abu Umamah?”
He said: I am remembering my Lord.
He said: “Shall I not tell you…” and he quoted the hadeeth (narration).
Al-Shaykh al-Albani (may Allah have mercy on him) said:
This hadeeth is narrated by Abu Umamah al-Bahili: Suday ibn ‘Ajlan, and attributed to the Prophet (peace and blessings of Allah be upon him), and there are a number of chains of transmission from him.
Then he listed the chains of transmission and said concerning al-Hakim’s narration of some of its isnads: al-Hakim said: It is saheeh according to the conditions of the two shaykhs (al-Bukhari and Muslim), and al-Dhahabi agreed with him, and it is as they said.
See: al-Silsilah al-Saheehah, no. 2578. He also stated that the hadeeth is saheeh in Saheeh al-Targheeb wa’l-Tarheeb, no. 1575
The hadeeth was classed as hasan (sound) by al-Hafiz Ibn Hajar in Nataij al-Afkar, 1/84. al-Haytham said in al-Majma’ 10/110: It was narrated by Ahmad and its men are the men of saheeh. It was classed as saheeh by the editors of Musnad Ahmad in the edition published by Muasasat al-Risalah, 36/459-460, where they discussed its isnads in detail.
As for what may be understood from the hadeeth, the most important of it is the virtue of this dhikr (words of remembrance) in particular, as the Prophet (peace and blessings of Allah be upon him) said that the one who recites it attains a great reward that is superior to most adhkar.
Hence al-Hafiz Ibn Khuzaymah (may Allah have mercy on him) included it in a chapter in his Saheeh (1/307) that he entitled Bab Fadl al-Tahmeed wa’l-Tasbeeh wa’l-Takbeer bi wasf al-‘Adad al-Katheer min khalq Allah aw ghayri khalqihi. End quote.
Ibn al-Qayyim (may Allah have mercy on him) said:
Saying: Subhan Allah wa bi hamdih, ‘adada khalqihi, wa rida nafsihi, wazinata ‘arshihi, wa midaada kalimatihi (Glory and praise be to Allah, as much as the number of His creation, as much as pleases Him, as much as the weight of His Throne and as much as the ink of His words) is many times better than merely saying Subhan Allah (Glory be to Allah). What the one who says “Subhan Allah wa bi hamdih, ‘adada khalqihi…” achieves of knowing Allah, exalting Him and glorifying Him, when his dhikr is connected to the huge numbers mentioned, is far greater than what is achieved by the one who merely says Subhan Allah. This is called multiplied dhikr and it is greater glorification and praise than regular dhikr, hence it is better than it.
This is manifested when we understand what this dhikr means:
When the worshipper says Subhan Allah wa bi hamdihi, ‘adada khalqihi, it is like a statement and explanation of what the Lord deserves of glorification the number of every created being, what has been and what will be, for eternity. It includes an affirmation that Allah is above all things, and glorifying and praising Him this huge number cannot be comprehended by anyone who counts; the end of it can never be reached. It includes the person's aspiration to do such endless tasbeeh (glorification of Allah). What the person says is not intended to limit the glorification to that number or level; rather he is saying that what Allah deserves of glorification is glorification which reaches that number even if it has no limit, because the creation of Allah will always be ongoing and will never be limited by a number or figure.
What is meant is that this tasbeeh has reached a level of perfection and majesty that indicates that it should be better than others and if something else were weighed against it, it would outweigh it. This is what some of these words refer to of the perfect qualities of Allah and praising Him by declaring Him to be above all things, in addition to praising Allah which implies the following:
i. Affirmation of His attributes of perfection
ii. Loving Him and being pleased with Him.
iii. If one adds to these praises, glorification and exaltation in the most perfect and sublime manner, the highest number of times, and the worshipper focuses on this glorification and contemplates its meaning, then this dhikr will have great virtue and advantages that are not shared by others. And Allah is the Source of strength.
Al-Manar al-Muneef, 34-38
And Allah knows best.