Prostration, or sujud, is the most noble position a worshipper can be in. It is the epitome of humility and submissiveness. When a persons prostrates, they lower their face – the most noble part of their body – to the dust, seeking the pleasure of His Lord. This is why this posture is most beloved by Allah, all praises and glory be to Him. Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet, peace be upon him, said:
“The closest any worshipper can be to his Lord is while he is in prostration, so increase your du’as in it.” (Recorded in Muslim)
For this reason, the Prophet, peace be upon him, was prohibited by Allah from reciting the Qur’an while in a state of ruku or sujud, and he, peace be upon him, prohibited other Muslims from doing this also. In Abbas, may Allah be pleased with hum, narrated that once the Prophet, peace be upon him, lifted the curtain from his house and looked into the mosque, and the people were lined in rows behind Abu Bakr (and this was during the illness from which he, peace be upon him, died). He then said:
“O people! There is nothing left of Prophethood except a trued dream, a Muslim sees it himself or someone else sees it for him (i.e. he sees the other person in a dream). And I have been prohibited from reciting the Qur’an while in ruku or sujud, so during ruku, glorify your Lord, and during sujud, excerpt yourself in making du’a, for it very likely that you will be responded to.” (Recorded in Muslim)
We should therefore strive to praise and glorify Allah as much as possible whilst bowing and to increase our du’a to Allah whilst in prostration, as this is the time when it is most likely to be responded to.
In regards to making du’a in the sujud in the prayer, it is best to say these in Arabic if know any du’as in Arabic, but if you do not, then it is permissible to ask Allah in your own language until such time as you learn them. Du’as from the Qur’an and the sunnah are particularly recommended for use in the prayer. Outside the prayer you can make any du’a in any language you wish. And Allah knows best.