وَ«أَنَّى» تُسْتَعْمَلُ تَارَةً بِمَعْنَى «كَيْفَ»
Annā is sometimes used with the sense of kayfa: how.
فَأْتُوا حَرْثَكُمْ أَنَّى شِئْتُمْ
So approach your tilth as you wish.
In this example the word is explained with reference to manner or way, rather than merely asking about a location. The specific legal and contextual implications are not derived from a dictionary equivalence alone.
The source also associates this usage with a verb following the expression, as in shiʾtum in this verse.