Parashas Shemos
וְלֹא־יָכְלָ֣ה עוֹד֮ הַצְּפִינוֹ֒ וַתִּֽקַּֽח־לוֹ֙ תֵּ֣בַת גֹּ֔מֶא וַתַּחְמְרָ֥הֿ בַחֵמָ֖ר וּבַזָּ֑פֶת וַתָּ֤שֶׂם בָּהּ֙ אֶת־הַיֶּ֔לֶד וַתָּ֥שֶׂם בַּסּ֖וּף עַל־שְׂפַ֥ת הַיְאֹֽר׃
When she could hide him no longer, she got a wicker basket for him and caulked it with bitumen and pitch. She put the child into it and placed it among the reeds by the bank of the Nile.
Torah Temimah points to Sotah 12a (verified).
ותשם בסוף — \ldots
English: She placed it among the reeds at the river’s edge, a place both hidden and accessible.
Custom
The placement was strategic: hidden yet at the water’s edge where a rescuer might find it.