40 Bhagavatha --Ulukala bandhanam

Yashoda was suckling Krishna in her lap. The milk which was kept on the oven for boiling began to overflow. Yashoda slowly placed Krishna down and rushed to  remove the boiling milk so that it may not flow over to the hearth. Krishna, having been disturbed, felt angry and broke the pot meant for churning the curds with a heavy stone. With tears in his eyes, he went to the interior of the house and ate fresh butter.  After removing the vessel from the hearth, Yashoda saw the broken pot and laughed heartily, knowing that it was Krishna's work.  She finds him standing on the overturned base of a wooden mortar and was giving butter to a monkey. Seeing his mother approaching him with a stick in her hand, from the corner of his eye, he gets down in haste and runs away, pretending to be afraid. Yashoda runs after her son and manages to catch hold of him. He was now weeping aloud and rubbing his eyes with his hands.  The kaajal in his eyes began to spread and his eyes were filled with fear. She cast off the stick and tried to bind him to the mortar
with a string. However, the string fell short by about an inch. She knotted together various strings available in the house and tried to bind him again. Still there was the same one inch of deficit. She tries yet again, but the shortage was the same one inch. Yashoda smiled, looking at the cowherd women smile at her frustration. She felt amazed that she could not bind Krishna. Her body was bathed in perspiration. Her braided hair loosened. Seeing the over-exertion of his mother, Krishna let himself be tied by her, out of compassion.
Lord Krishna noticed a pair of Arjuna trees, who were the sons of Kubera in the previous birth, Nalakubara and Manigriva. Narada, who happened to see the arrogant sons of Kubera bathe in the river Ganga in an intoxicated state with no clothes on, cursed them to become trees (and remain self conscious in that state). They will get back their form of yakshas, after Vasudeva graces them.
Krishna slowly proceeds to the spot where the two trees stood, to make the word of his exalted devotee Narada come true.  He crawled between the two trees. He passed through, pulling the mortar behind him. The mortar fell crosswise. The vehement dragging of the mortar by Krishna uprooted the gigantic trees and both fell down with a terrific crash, their trunk, leaves, and boughs violently shaken by the force exerted by Krishna. Nalakubara and Manigriva arose from that spot illuminating the whole quarters with their splendour, shorn of all their pride.  They extoll Krishna. "Hail to you, O Vasudeva, your auspicious sight has been possible to us only through the grace of the divine sage Narada. Let our speech be employed hereafter in recounting your excellence, our ears in hearing your stories, our hands in doing your work, and our mind in the thought of your feet."  Krishna, still tied to the mortar, laughingly spoke to the twin yakshas.
"The kind-hearted sage Narada has graced you with his curse, as you were blinded by the pride of your fortune. O Nalakubara and Manigriva, return to your abode. Supreme devotion has already been kindled in you, due to which you will realise the highest goal." The two yakshas circumambulate the Lord and take leave of him.
Hearing the crash of the trees, the cowherds led by Nanda rush to the spot. They were bewildered when they saw Krishna standing safe amidst the fallen trees. The infants playing there tried to tell them that Krishna had dragged the mortar through the trees which caused it to fall and also that they saw two men rising from there. The cowherds dismissed it as child talk. Nanda untied Krishna from the mortar and set him free.