Exodus 13:16

ולטטפת this denotes the Tephillin; and because they consist of four houses (compartments) they are called טטפת, for טט denotes “two” in Katpi and פת in Afriki denotes “two״ (Sanhedrin 4b). Menachem ben Seruk, however, placed it in the same section (gave it the same meaning) as, (Ezekiel 21:2) “And speak (הטף) to the south״; and as, (Micah 2:6) “speak ye (תטיפו) not”; so that טטפת would be an expression denoting “speaking”, and corresponds to ולזכרון (in v. 9 where it really replaces טוטפת), because whoever sees them (the Tephillin) bound between the eyes will remember the miracle (so that they become a זכרון, a reminder) and will speak about it (so that they become a טטפת. something that causes one to speak about the miracle).

וְהָיָ֤ה לְאוֹת֙ עַל־יָ֣דְכָ֔ה וּלְטוֹטָפֹ֖ת בֵּ֣ין עֵינֶ֑יךָ כִּ֚י בְּחֹ֣זֶק יָ֔ד הוֹצִיאָ֥נוּ יְהֹוָ֖ה מִמִּצְרָֽיִם׃ {ס}        

And it shall be for a token upon thy hand, and for frontlets between thy eyes: for by strength of hand the Lord brought us forth out of Miżrayim.