step by step

in a gradual manner; "the snake moved gradually toward its victim"

अतः तुम मुझे छोड़ दो और उसको जो इस वाणी को झुठलाता है। हम ऐसों को क्रमशः (विनाश की ओर) ले जाएँगे, ऐसे तरीक़े से कि वे नहीं जानते

So leave those who deny this Discourse to Me. We shall lead them step by step to (ruin) in a way they will not know.