What is the ruling on saying "Samu Alaykum" with the intention of [saying] "Al-Salam Alaykum"?

The Sunnah concerning the greeting of peace is for a Muslim to say: "As-salamu alaykum" (Peace be upon you). As for saying: "As-salamu ala man ittaba'a al-huda" (Peace be upon whoever follows guidance), it is a grave error and a linguistic distortion of the salutation that should be avoided. The Jews used to greet the Prophet, peace and blessings be upon him, with a similar phrase, saying: "As-samu alaykum" (Death be upon you), intending thereby to invoke death upon him.