“Give every sūrah its due share of bowing and prostration.”

Narrated by Aḥmad (nos. 20590, 20651), Ibn Abī Shaybah (no. 949), and al-Bayhaqī in al-Sunan al-Kubrā (nos. 4694, 4695), from the narration of a man among the Companions (may Allah be pleased with them).
Also narrated by al-Ṭabarānī in al-Muʿjam al-Kabīr (no. 9856), from the narration of ʿAbd Allāh ibn Masʿūd (may Allah be pleased with him).
Authenticated in Ṣaḥīḥ al-Jāmiʿ (no. 1054) and in Aṣl Ṣifat al-Ṣalāh (1/396).

Brief Explanation of the Hadith

It is from the Sunnah that the prayer of the worshipper be balanced and proportionate in its pillars — maintaining moderation between recitation, bowing, and prostration — as mentioned in the ḥadīth of ʿAbd Allāh ibn Masʿūd (may Allah be pleased with him), that the Messenger of Allah (may Allah’s peace and blessings be upon him) said: “Give every sūrah its due share of bowing and prostration.”
What is meant by “sūrah” here is that which is recited after Sūrat al-Fātiḥah. A number of scholars have interpreted this ḥadīth to mean that when a person lengthens his recitation, he should maintain balance in his prayer — not prolonging the standing while hastily shortening the bowing and prostration — but rather giving each pillar of the prayer its due share of remembrance, humility, and tranquillity. This ensures the perfection of the prayer and the presence of the heart within it. The intended meaning, therefore, is not that the duration of bowing and prostration should be nearly equal to that of the standing.
As evidenced by what Muslim narrated from the narration of al-Barā’ ibn ʿĀzib (may Allah be pleased with him), who said:“I observed the prayer along with Muḥammad (may Allah’s peace and blessings be upon him), and I found his standing, his bowing, his standing upright after bowing, his prostration, his sitting between the two prostrations, his prostration (again), and his sitting between the salām and departure — to be nearly equal in length.”
In another narration: “Except for the standing and the sitting, they were nearly equal in length.”
Some scholars have interpreted the ḥadīth to mean that each rakʿah should be assigned a single sūrah after Sūrat al-Fātiḥah — that multiple sūrahs should not be combined within one rakʿah, nor should a single sūrah be divided between two rakʿahs — so that every portion of the Qur’ān is recited within its own distinct bowing and prostration, receiving its proper share of remembrance and humility.