Labbayk-Allāhumma labbayk,
labbayka lā sharīka laka labbayk,
inna ‘l-ḥamda, wanni`mata, laka wa ‘l-mulk,
lā sharīka lak.
I am here at Your service, O Allah, I am here at Your service.
I am here at Your service, You have no partner, I am here at Your service.
Surely the praise, and blessings are Yours, and the dominion.
You have no partner.
Reference:
Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 3/408, Muslim 2/841.