Shuklambara Brahmachari was the incarnation of one of the yajna-patnis who gave food in charity to Krishna and His friends. Lord Chaitanya was accustomed to eating food He had begged from Shuklambara Brahmachari. Some say that Shuklambara Brahmachari was not one of the yajna-patnis, but one of their husbands, the yajnika-brahmanas.
CC Adi 10.38 purport describes Shuklambara Brahmachari:
Shuklambara Brahmachari, an inhabitant of Navadwipa, was Lord Chaitanya Mahaprabhu’s first companion in the sankirtan movement. When Lord Chaitanya returned from Gaya after initiation, He stayed with Shuklambara Brahmachari because He wanted to hear from this Devotee about the pastimes of Lord Krishna. Shuklambara Brahmachari collected alms of rice from the inhabitants of Navadwipa, and Shri Chaitanya Mahaprabhu took pleasure in eating the rice that he cooked. It is said that Shuklambara Brahmachari was one of the wives of the yagnic brahmanas during the time of Lord Krishna’s pastimes in Vrindavana. Lord Krishna begged food from the wives of the yagnic brahmanas, and Lord Chaitanya Mahaprabhu performed a similar pastime by begging rice from Shuklambara Brahmachari
Purport to CC Adi 17.20:
Shuklambara Brahmachari resided in Navadwipa on the bank of the Ganges. When Shri Chaitanya Mahaprabhu was dancing in ecstasy, he approached the Lord with a begging bag containing rice. The Lord was so pleased with His Devotee that He immediately snatched the bag and began to eat the raw rice. No one forbade Him, and thus He finished the entire supply of rice.
The most fortunate beggar
Now hear how Lord Gauranga showed His special mercy upon Shuklambara Brahmachari, a native of Navadwipa and who was then standing in front of the Lord. He was very righteous and peaceful, always performing his duties, no one knew what an exalted Devotee he was. He went around the Navadwipa town with a cloth bag over his shoulder, begging from house to house. He was constantly chanting Krishna's name and tears streamed down his eyes at the recitation of the Lord's name.
People treated him with the usual disdain reserved for the beggars, but the brahmana begged from everyone, even from improvises dwellings. At the end of the day he collected everything and first offering it to Krishna he ate the remnant. He never experienced the sad chills of poverty by the grace of the Holy Name of Krishna, love of Krishna made him ever blissful as he went to each door and chanted Krishna. Who can recognize a Devotee of Lord Chaitanya other than a person who has received Lord Chaitanya's mercy.
Shuklambara, the poor and devoted brahmana was just like Shridama, Krishna's friend. He was always inside the house seeing Lord Chaitanya dance, this was certainly the Lord's special mercy.
The Lord was seated on the throne in the mood of the Supreme Controller Godhead. He saw Shuklambara Brahmachari join the dancing, a cloth bag was hanging down from his shoulder. He was dancing with carefree glee, the Lord and the Devotees enjoyed the sight and laughed. The munificent Lord addressed Shuklambara endearingly asking him to come nearer.
The Lord said, "Birth after birth you have been My impoverished Devotee, offering Me everything and remaining a beggar yourself. I also desire for your offerings all the time, and if you do not give Me I must have it by force then. In Dwaraka I had snatched away the sack of chipped rice you kept concealed and when I started eating from it Rukumi Devi had taken hold of My hand to stop Me."
The Lord then plunged His hand inside Shuklambara's bag and picked up handfuls of husked rice putting it inside His mouth and began chewing it. Shuklambara hastily said, "O Lord what have You done, this rice is full of broken rice chips." The Lord replied, "I eat with delight your chipped rice pieces, but I will never accept or ask for nectar from a non-Devotee."
The Lord who is the life and soul of the Devotees is fully independent and always submerged in the highest state of transcendental bliss, who could forbid Him from eating the chipped rice. The Devotees marveled at the Lord's unlimited compassion, holding their heads in their hands, they wept profusely in joy rolling about oblivious of everything as they had never seen such kindness before.
The above story can be found in Shri Vrndavan Das's Chaitanya Bhagavat Mahya-lila Chapter 16.