To what extent is the hadith "Watching an hour is better than seventy years of worship" authentic, and does it have a basis in the books of the Six Hadith Collections?

The Hadith "An hour's deliberation is better than sixty years of worship" is falsely attributed to the Prophet, peace and blessings be upon him. Its chain of narration includes liars and fabricators.

As for contemplation on the signs of Allah, it has been praised in the Holy Quran, as in His saying, the Most High: "Those who remember Allah while standing or sitting or [lying] on their sides and give thought to the creation of the heavens and the earth, [saying], 'Our Lord, You did not create this in vain. Exalted are You! Protect us from the punishment of the Fire.'" (Quran 3:191) And there are narrations from the early Muslims (Salaf) that call for contemplation, among them the saying of Ibn Abbas: "An hour's deliberation is better than a night's prayer," and this was also narrated from Al-Hasan Al-Basri and Abu Ad-Darda'.

Contemplation of created things is commanded and encouraged; it is an act of worship characteristic of Allah's knowing saints.