Cambridge University Library T-S E2.51 preserves an early Eastern version of the Mishnah, Tractate Pesaḥim. The upper part of the same parchment leaf, housed at the Bodleian Library in Oxford, Heb. C. 27/27, contains the conclusion of Tractate ʿEruvin. Both pieces have been catalogued and occasionally cited for textual variants.1 Yet one striking feature has gone unnoticed: this leaf is a Hebrew palimpsest.
Elyashiv Cherlow (Tue,) studied this question.