Jamieson, Fausset and Brown on Ezekiel 16:4

4. Israel's helplessness in her first struggling into national existence, under the image of an infant (Ho 2:3) cast forth without receiving the commonest acts of parental regard. Its very life was a miracle (Ex 1:15-22).

navel ... not cut--Without proper attention to the navel cord, the infant just born is liable to die.

neither ... washed in water to supple thee--that is, to make the skin soft. Rather, "for purification"; from an Arabic root [Maurer]. Gesenius translates as the Margin, "that thou mightest (be presented to thy parents to) be looked upon," as is customary on the birth of a child.

salted--Anciently they rubbed infants with salt to make the skin firm.