यदभ्यासेन तद्भावो भवेद्भ्रमरकीटवत् ।अत्रापहाय सन्देहमभ्यसेत्कृतनिश्चयः ॥ १९ ॥
In plain words
What you practice, you become — the grub stares at the wasp until it is a wasp. So here: drop the doubt, make up your mind, and practice.
Close to the Sanskrit
By the repeated practice of which, the state of that comes to be, like the wasp and the grub. Here, having cast off doubt, one of settled resolve should practice.