mựa

Likely from ultimately Proto-Sino-Tibetan *ma. Compare Burmese မ (ma.), Lisu ꓟꓽ (mɑ̀), Old Chinese 毋 (OC *mo) (phonetically confused with and read like 無 (OC *ma) even in Zhou time), etc.

If this were

non-Sino-Vietnamese reading of Chinese 毋 (“injunctive and imperative negative; do not, should not, must not”, SV: vô, mưu), then its nặng-tone (instead of expected **huyền) has resulted from either borrowing from a regional Chinese dialect (see tạnh), or indirect borrowing (see tiếng), or an irregular pre-Middle Chinese sound change (see vẹn and nhặng).

• (Hà Nội) IPA^(key): [mɨə˧˨ʔ]
• (Huế) IPA^(key): [mɨə˨˩ʔ]
• (Saigon) IPA^(key): [mɨə˨˩˨]

mựa • (馬, 駡, 𱐾, 嗎)

1. (prohibitive marker, obsolete) don't

   Synonym: đừng

   • 15th century, Nguyễn Trãi, “謾述 Mạn thuật 3”, in Quốc âm thi tập (國音詩集):

     義(Nghĩa)仁(nhân)礼(lễ)智(trí)馬(mựa)朱(cho)亐(khuây)

     Probity, humaneness, propriety, wisdom; do not let them dwindle!

   • Tân biên Truyền kỳ mạn lục tăng bổ giải âm tập chú (新編傳奇漫錄增補解音集註 "Newly Edited Collection of Truyền kỳ mạn lục with Supplemented Annotations, Phonetic Explanations, and Collected Notes"), volume 3; 55a

     𤽗貰𠃣除，𱐾嫌悶丕。

     Ngươi thế ít chờ, mựa hiềm muộn vậy.

     Please wait for a moment sir, don't worry about being late.