Parashas Shemos
וַתֵּ֥לֶךְ הָעַלְמָ֖ה וַתִּקְרָ֣א אֶת־אֵ֥ם הַיָּֽלֶד׃
And the almah went and called the child’s mother.
Torah Temimah points to R’ Elazar / R’ Shmuel bar Nachmani — Sotah 12b (verified).
ותלך העלמה — ר׳ אלעזר אומר העלמה – מלמד שהלכה בזריזות כעלמה; ור׳ שמואל בר נחמני אמר – שהעלימה את דבריה.
English: “And the almah went” — R’ Elazar said: almah teaches that she went with the alacrity of a young woman; R’ Shmuel bar Nachmani said: she concealed (he’elimah) her words.
Custom
Miriam’s action is praised either for its swiftness or for the discretion with which she reunited mother and child.