שְׁלֹשָׁ֣ה הֵ֭מָּה נִפְלְא֣וּ מִמֶּ֑נִּי וארבע [וְ֝אַרְבָּעָ֗ה] לֹ֣א יְדַעְתִּֽים׃
There are three things which are too wonderful for me, Yea, four which I know not:
Read kabbalistic (mystical) interpretation of Proverbs 30:18: and classical mystical sources.