Your Lordship previously accepted incarnations as a fish, a horse, a tortoise, Narasimhadeva, a boar, a swan, Lord Ramacandra, Parasurama and, among the demigods, Vamanadeva, to protect the entire world by Your mercy - SB 10.2.40

Expressions researched:
"Your Lordship previously accepted incarnations as a fish, a horse, a tortoise, Narasimhadeva, a boar, a swan, Lord Ramacandra, Parasurama and, among the demigods, Vamanadeva, to protect the entire world by Your mercy"

SB Canto 10.1 to 10.13

O supreme controller, Your Lordship previously accepted incarnations as a fish, a horse, a tortoise, Narasiṁhadeva, a boar, a swan, Lord Rāmacandra, Paraśurāma and, among the demigods, Vāmanadeva, to protect the entire world by Your mercy. Now please protect us again by Your mercy by diminishing the disturbances in this world. O Kṛṣṇa, best of the Yadus, we respectfully offer our obeisances unto You.

SB 10.2.40, Translation and Purport:

O supreme controller, Your Lordship previously accepted incarnations as a fish, a horse, a tortoise, Narasiṁhadeva, a boar, a swan, Lord Rāmacandra, Paraśurāma and, among the demigods, Vāmanadeva, to protect the entire world by Your mercy. Now please protect us again by Your mercy by diminishing the disturbances in this world. O Kṛṣṇa, best of the Yadus, we respectfully offer our obeisances unto You.

In every incarnation, the Supreme Personality of Godhead has a particular mission to execute, and this was true in His appearance as the son of Devakī in the family of the Yadus. Thus all the demigods offered their prayers to the Lord, bowing down before Him, and requested the Lord to do the needful. We cannot order the Supreme Personality of Godhead to do anything for us. We can simply offer Him our obeisances, as advised in Bhagavad-gītā (man-manā bhava mad-bhakto mad-yājī māṁ namaskuru (BG 18.65)), and pray to Him for annihilation of dangers.