RESIGNATION. The literal meaning of Islam is a state or condition in which a believer becomes “resigned” to the will of God, a “Muslim” being one who is “resigned.” But in the Qur’an, the grace of resignation is more frequently expressed by the word sabr, – “patience,” e.g. Surah ii. 150: “Give good tidings to the patient, who when there falls on them a calamity, say, ‘Verily we are God’s and verily to Him do we return.'”
The word Taslim, which the compiler of the Kitabu ‘t-Ta’rifat says means to place one’s neck under the commands of God, seems to express the EngIish word resignation.”
It occurs in the Qur’an, Surah iv. 68:
“They submit with submission.”
The author of the Akhlaq-i-Jalali says Taslim is to “acquiesce in and receive with satisfaction (although. perhaps repugnant to the inclination) the commands of God,” as exemplified in the verse above quoted.
Riza. is also a word which expresses resignation, and is defined as being pleased with the inevitable decrees of God, whatever they may be.

Based on Hughes, Dictionary of Islam