This is an authentic hadith. Ibn Majah (1) recorded it, transmitting from a trustworthy narrator, from Sufyan ibn ʿUyaynah.
It is also found in Sahih al-Bukhari, through the chain of al-Thawri from Abu Hazim al-Aʿraj. ʿAbd al-Hafiz ibn Badran and Yusuf ibn Ahmad informed us, saying: Musa ibn ʿAbd al-Qadir related to us; Saʿid ibn Ahmad related to us; ʿAli ibn Ahmad related to us; Muhammad ibn ʿAbd al-Rahman al-Dhahabi related to us; ʿAbd Allah ibn Muhammad related to us; Khalaf ibn Hisham related to us; al-ʿAttaf ibn Khalid related to us; Abu Hazim related to us, from Sahl ibn Saʿd:
“I heard the Messenger of Allah ﷺ say: ‘A morning spent in the path of Allah, or an evening spent in the path of Allah, is better than the world and all that it contains; and a spot in Paradise the size of a whip is better than the world and all that it contains.’ (2)
Al-Tirmidhi also recorded it through al-ʿAttaf’s narration and declared it authentic.
And it is in al-Bukhari,
(1) Hadith no. 1035 in the Book of Establishing the Prayer, chapter “Tasbih for men during the prayer and clapping for women,” transmitted by Hisham ibn Ammar and Sahl ibn Abi Sahl, who said: Sufyan ibn Uyaynah related to us, from Abu Hazim, from Sahl ibn Saʿd al-Saʿidi: the Messenger of Allah (peace be upon him) said, “Tasbih (saying Subhan Allah) is for men, and clapping is for women.” A longer version is recorded by Malik in al-Muwattaʾ, 1/163–164, Book of Shortening the Prayer while Travelling, chapter “Turning and clapping when necessary,” through Abu Hazim, from Sahl ibn Saʿd. Al-Bukhari cites it, 2/139, 141, in the Book of Congregational Prayer, chapter “Whoever enters to lead the people,” through ʿAbd Allah ibn Yusuf; Muslim, no. 421, in the Book of Prayer, chapter “The congregation designates the one who will lead them,” through Yahya ibn Yahya; and Abu Dawud, no. 940, in the Book of Prayer, chapter “Clapping in the prayer,” through al-Qaʿnabi—all three on the authority of Malik, from Abu Hazim, from Sahl ibn Saʿd. That narration contains the Prophet’s words: “Why do I see you clapping so much? If something happens to a man in his prayer, let him say Subhan Allah; when he says it, people will pay attention to him. Clapping is for women.”
(2) Reported by al-Tirmidhi, no. 1648, in the Book of the Merits of Jihad, chapter “The virtue of setting out in the morning or evening in the path of Allah.” Also recorded by al-Bukhari in the Book of Jihad, chapters “Setting out in the morning or evening in the path of Allah” and “The merit of guarding the frontier for a day in the path of Allah,” in the Book of the Beginning of Creation, chapter “Description of Paradise,” and in the Book of Softening the Hearts, chapter “The parable of this world and the hereafter.” Muslim, no. 1881, includes it in the Book of Leadership, chapter “The virtue of setting out in the morning or evening in the path of Allah.”