The Rebbe blesses the writer and his wife with health and nachas from their children. He suggests starting the custom of saying Tehillim in shul during the week and sharing the Frierdiker Rebbe’s words about its power. A recent Lag BaOmer sicha is enclosed, which should be read, at least in part, to the congregants for their benefit.
https://www.torahrecordings.com/rebbe/004_igros_kodesh/iyar/1008