What is the correct ruling regarding returning to perform the tasbeeh that was unintentionally omitted in rukoo’ (bowing) or sujood (prostration), and is the obligation waived due to forgetfulness?

Scholarly opinions differ regarding the ruling on tasbeeh (glorification of Allah) during bowing (ruku’) and prostration (sujood). While the majority of scholars consider it to be mustahabb (recommended), Imam Ahmad views it as wajib (obligatory).

As for someone who forgot the tasbeeh and remembered it before rising from bowing or prostration, they should say it. However, if they remember it after rising, they are not permitted to return to it, and they should perform the prostration of forgetfulness (sujood as-sahw). The Shaykh mentioned in "Al-Mulakhkhas al-Fiqhi" that whoever omits the tasbeeh in bowing or prostration must return to perform it, as long as they have not yet stood upright in the next rak'ah. This might be attributed to a narration from Imam Ahmad stating that tasbeeh is an essential pillar (rukn) of the prayer.