Why are Vitthal Rakhumai separate?

Rukmini (Rakhumai) the chief queen of Lord Krishna (Vitthal) went with him to sage Durvasa to invite him to Dwarka. He agreed to it on a condition that they (Lord Krishna and Rukmini) will have to pull the chariot carrying sage Durvasa. Lord Krishna and Rukmini happily said yes to do so. While driving the chariot, Rukmini became thirsty. She sought the help of Lord Sri Krishna. In order to quench her thirst Lord Krishna stopped the chariot and made water of Holy River Ganga come out and flow by digging with his toe on the ground.

Rukmini took a sip without offering Rishi Durvasa Annoyed by her impoliteness he cursed Rukmini that she would be separated from her beloved husband. Rukmini Devi did penance for 12 years at this spot to get rid of the curse and finally pleased with her sincere prayers Lord Mahavishnu came in front of her and the curse got dissolved. Thus after twelve years of separation Rukmini and Lord Krishna met and lived together happily. There is a temple in Dwarka on the place where Rukmini did her penance. The temple walls are decorated with beautiful paintings which depict her pastimes with Lord Krishna. This temple is said to date back to the 12th century.There is a beautiful marble deity of Rukmini Devi with Chaturbhujas (four hands). This depicts that she is Sri the wife of Narayana in Vaikuntha.

Adi Sankara in Pandurangashtakam said

"Ajam Rukminnii-Praanna-San.jiivanam Tam

Param Dhaama Kaivalyam-Ekam Turiiyam |

Prasannam Prapanna-[A]artihan Deva-Devam

Parabrahma-Linggam Bhaje Paanndduranggam ||8||

Salutations to Sri Pandurang) Who is without Birth and Who enlivens the Life of Devi Rukmini (by His Love), Who is the one Supreme Abode of Kaivalya in the (fourth) state of Turiya, Who is Gracious to His Devotees, and removes the Distress of those who seek His Refuge; Who is the Deva of the Devas [God of the Gods]. I Worship that Pandurang, Who is the veritable Image (Lingam) of Parabrahman. Rukmini is Rukmabai who gets miffed with Krishna and leaves Dwaraka as per the legend. Unable to bear her separation, Krishna reaches her and pacifies her. Then he goes to Pundarika, a great devotee who serves his parents and asks the lord to wait. Krishna becomes Pandurang and stays there. Rukmabai is Rukmini, his spouse who is always with him anywhere and everywhere.

According to mythology, Vithoba is believed to be the incarnation of Lord Krishna. Moved by the sincere devotion of Rishi Pundalik towards his parents Lord Krishna decided to visit Pundalik’s home. He assumed the form of a small boy that of Gokul Krishna and visited Pundalik’s home. Pundalik saw the Lord at his door but his devotion to his parents was so intense that he wanted to finish his duties first and then attend to his guest. He had reached such a stage that it didn’t matter to him whether the guest was a mere mortal or God. All that mattered was service to his parents.

He gave the Lord a brick to stand on and asked him to wait until his duty was completed. Moved by this devotion of Pundalik to his parents Lord Krishna blessed him and asked him to ask a boon. Pundalik asked that the Lord should remain on earth and bless and take care of his devotees. Lord Krishna agreed to stay there and is known as Vithoba or the Lord who stands on a brick. The present deity of Pandurang is in this posture, that of a small boy waiting patiently on a piece of brick.

The hands on the hip actually reflects the boyish nature of Lord Krishna. This form of the Lord Vithoba is Swayambhu which means that his deity has not been carved or etched but it came into existence on its own.  In this duration, Mother Rukmini, forgetting Her distress and unable to keep Herself away from Her Lord, came to Pandharpur and took Her place beside Krsna. And to this day, both Lord and Lady, are ever-present in Pandharpur in Their deity form, waiting for Their devotees to come and take darshan, and be blessed! Jay Pandurang Vitthala