Samekh
Samekh or Simketh is the fifteenth letter of many Semitic abjads, including Phoenician Ṣāmek 
, Hebrew ˈSamekh ס, Aramaic Semkath 
, Syriac Semkaṯ ܣ, representing /s/. The Arabic alphabet, however, uses a letter based on Phoenician Šīn to represent /s/ (see there); however, that glyph takes Samekh's place in the traditional Abjadi order of the Arabic alphabet.
The Phoenician letter gave rise to the Greek Xi (Ξ, ξ).
Origins
The origin of Samekh is unclear. The Phoenician letter may continue a glyph from the Middle Bronze Age alphabets, either based on a hieroglyph for a tent peg / some kind of prop (s'mikhah, Hebrew: סמיכה, or t'mikhah, Hebrew: תמיכה, in modern Hebrew means to support), and thus may be derived from the Egyptian hieroglyph djed.
Hebrew Samekh
Hebrew spelling: סָמֶךְ
Pronunciation
Samekh represents a voiceless alveolar fricative /s/. Unlike most Semitic consonants, the pronunciation of /s/ remains constant between vowels and before voiced consonants.
Significance
Samekh in gematria has the value 60.
Samekh
I hate double-minded men,
But I love your law.
You are my refuge and my shield;
I have put my hope in your word.
Away from me, you evildoers,
That I may keep the commands of my God!
Sustain me according to your promise, and I will live;
Do not let my hopes be dashed.
Uphold me, and I will be delivered;
I will always have regard for your decrees.
You reject all who stray from your decrees,
For their deceitfulness is in vain.
All the wicked of the earth you discard like dross;
Therefore I love your statutes.
My flesh trembles in fear of you;