One verse

Srimad Bhagavatam 9.10.2

9.10.2

तस्यापि भगवानेष साक्षाद् ब्रह्ममयो हरि: । अंशांशेन चतुर्धागात् पुत्रत्वं प्रार्थित: सुरै: । रामलक्ष्मणभरतशत्रुघ्ना इति संज्ञया ॥ २ ॥

tasyapi bhagavan esa saksad brahmamayo harih amsamsena caturdhagat putratvam prarthitah suraih rama-laksmana-bharata- satrughna iti samjnaya

tasya
of him, Maharaja Dasaratha
api
also
bhagavan
the Supreme Personality of Godhead
esah
all of them
saksat
directly
brahma-mayah
the Supreme Parabrahman, the Absolute Truth
harih
the Supreme Personality of Godhead
amsa-amsena
by an expansion of a plenary portion
caturdha
by fourfold expansions
agat
accepted
putratvam
sonhood
prarthitah
being prayed for
suraih
by the demigods
rama
Lord Ramacandra
laksmana
Lord Laksmana
bharata
Lord Bharata
satrughnah
and Lord Satrughna
iti
thus
samjnaya
by different names

Being prayed for by the demigods, the Supreme Personality of Godhead, the Absolute Truth Himself, directly appeared with His expansion and expansions of the expansion. Their holy names were Rama, Laksmana, Bharata and Satrughna. These celebrated incarnations thus appeared in four forms as the sons of Maharaja Dasaratha.