It is ironic that the story about the Satavahana king [repeated often, starting at least with Kathaasaritsaagara, where the lady says 'modakair maam taaDaya'] ] is repeated here so soon after the discussion about "Conversational Sanskrit" and its shortcomings. And it is not ironic they way you probably thought. I suggest that you look away from the screen and think about what I might mean before reading the spoiler below.
---------------------------------------
So, here is the relevant extract from kaazikaa [the etext I have is in Roman transliteration, with some sandhis, but not all, split up. No, I am not going to fix it up.]
māṅi luṅ || PS_3,3.175 ||
māṅi upapade dhātoḥ luṅ pratyayo bhavati. sarvalakārāṇām apavādaḥ.
[examples] mā kārṣīt, mā hārṣīt /
[here it comes] katham mā bhavatu tasya pāpam, mā bhaviṣyati iti? asādhur eva ayam.
[rationalization by some others, of very questionable plausibility] kecid āhuḥ, aṅidaparo mā-śabdo vidyate, tasya ayaṃ prayogaḥ.
sma-uttare laṅ ca || PS_3,3.176 ||
sma-śabda-uttare māṅi upapade dhātoḥ laṅ pratyayo bhavati, cakārāl luṅ ca /
mā sma karot / mā sma kārṣīt / mā sma harat / mā sma hārṣīt //
----------------------------
Here is the historical/socio-linguists' explanation:, In Prakrits, where finite past tense forms disappeared, maa came to be used with the imperative, a very natural substitute (found in many other languages), but also less commonly the future. "Conversational Sanskrit" of the day calqued[1] Prakrit, but die-hard traditionalists frowned upon this. Eventually the new usage became accepted unquestioningly. Today, proponents of "conversational Sanskrit" calque Hindi/Kannada etc, ... So it goes.
-Nath Rao
[1]: So I use denominative berbs at will. Saves typing.