Aged 21 years and living in Langendorf when he married in 1825 so born 1803-04.

The wrong parents

Two otherwise credible sources attribute the wrong parent to the Israel Riesenfeld who married Jettel Schwarz. The definitive attribution comes from the record of that marriage which names Israel's parents as leather trader Abraham and the late Amalie. The JRI-Poland record of the birth of Rebecca (Friederike) names her parents as Israel Abraham Riesenfeld and Jettel Schwarz, the patronym leaving no doubt as to Israel's father's name.

• Friedrich Nothmann writes that Lazarus Riesenfeld of Langendorf, family number 2809, is the father of Israel Riesenfeld (1801-1866) and grandfather of Friederika Nothmann geb. Riesenfel (1826-1878); and that Benjamin Koppel (Jacob) Schwatz is the father of Jettel Riesenfeld geb. Schwartz (1794-1848, the other grandfather of Friederike.
• hirschfeld.se identifies Israel's parents as Loebel Riesenfeld and "Theresie KAZIORUNKE? (MAYER?)". This appears to be a confusion with a namesake