SB 10.8.26

kālenālpena rājarṣe
 rāmaḥ kṛṣṇaś ca gokule
aghṛṣṭa-jānubhiḥ padbhir
 vicakramatur añjasā
Word for word: 
kālena alpena — within a very short time; rājarṣe — O King (Mahārāja Parīkṣit); rāmaḥ kṛṣṇaḥ ca — both Rāma and Kṛṣṇa; gokule — in the village of Gokula; aghṛṣṭa-jānubhiḥ — without the help of crawling on Their knees; padbhiḥ — by Their legs alone; vicakramatuḥ — began to walk; añjasā — very easily.
Translation: 
O King Parīkṣit, within a very short time both Rāma and Kṛṣṇa began to walk very easily in Gokula on Their legs, by Their own strength, without the need to crawl.
Purport: 

Instead of crawling with Their knees, the babies could now stand up by holding on to something and walk little by little, without difficulty, by the strength of Their legs.