וְאִם־יִמְעַ֣ט הַבַּיִת֮ מִהְיֹ֣ת מִשֶּׂה֒ וְלָקַ֣ח ה֗וּא וּשְׁכֵנ֛וֹ הַקָּרֹ֥ב אֶל־בֵּית֖וֹ בְּמִכְסַ֣ת נְפָשֹׁ֑ת אִ֚ישׁ לְפִ֣י אָכְל֔וֹ תָּכֹ֖סּוּ עַל־הַשֶּֽׂה׃
and if the household be too little for a lamb, then shall he and his neighbour next unto his house take one according to the number of the souls; according to every man’s eating ye shall make your count for the lamb.
Read kabbalistic (mystical) interpretation of Exodus 12:4: and classical mystical sources.