The Messenger of Allah ﷺ said, "This world compared to the Hereafter is nothing more than what one of you would get if he dipped this finger of his into the sea. Let him see what comes back on it." And he pointed with his index finger.
حدثنا وكيع قال حدثنا إسماعيل بن أبي خالد عن قيس
قال رسول الله ﷺ ما الدنيا في الآخرة إلا كمثل ما يجعل أحدكم إصبعه هذه في اليم فلينظر بما يرجع وأشار بالسبابة
Its isnad is sahih, its narrators are famous imams, and Qays is Ibn Abu Hazim. The hadith was narrated by Muslim, 4/2193, no. 2858, in the Book of Paradise, on the transience of this world, and by Tirmidhi, 4/561, no. 2323, who said, hasan sahih, in the Book of Zuhd, on what has been said about the insignificance of this world, and by Ibn Majah, 2/1376, no. 4108, in a similar wording, and by Hakim, 4/319, and Dhahabi concurred with him.